In the context of the present invention, the term ‘fuel’ includes all possible types of energy source, i.e. not just liquid fuels but also, in particular, gas and electricity. Therefore, ‘fuel filler neck’ should be understood to mean, in particular, filler necks for fluid fuels as well as gas connection couplings and connection plugs for electrical power.
A closure of the above-mentioned type is known from DE 42 42 598 A1. In the case of the closure described therein, the closure part is movable by means of a guide slot such that, during the opening process, the closure part is initially raised somewhat perpendicularly relative to the orifice, and subsequently tilted away laterally relative to the external wall of the neck. The closure part is raised from the orifice of the neck by means of a rod-type operating lever, which is hinged at an end outside of the neck and at a distance therefrom is coupled to a pivot axis about which the closure part can execute a circular pivoting movement. A tension spring is fastened to a bearing outside the neck at one end and to the closure part at the other, in order to exert on the closure part a pretensioning force which forces the closure part back in the closing direction.
Based on this prior art, the object of the invention is to create a closure in which the closure part can be closed in an especially simple and reliable manner, which closure is optimised in terms of safety aspects, prevents any unauthorised opening of the closure by having a simple, space-saving design and, in addition, is as universally applicable as possible.
This object is achieved according to the invention by means of a closure with the features of claim 1. Advantageous embodiments of the invention are described in the further claims.
In the closure according to the invention, a spring mechanism is provided which is formed as a tightening device for drawing the closure part automatically into its final closed position.
Furthermore, the operating lever is hingedly-connected to the closure part by means of a second guide slot, which, when an opening force is introduced via the closure part, blocks the movement of the closure part from its closed position in the opening direction.
Owing to the fact that the spring mechanism automatically draws the closure part shut as far into its final closed position, no costly supplementary devices are necessary for this purpose. The closure according to the invention can be installed simply, cost-effectively and in a space-saving manner. It is especially advantageous in that, in the final closed position of the closure part, the spring mechanism retains the operating lever in a position in which a self-locking takes place between the operating lever and closure part via the second guide slot such that the closure part cannot be opened from outside, i.e. by grasping the closure part. This offers a high degree of security against any unauthorised opening of the closure as well as against accidental opening, i.e. the closure offers high crash security.
It is further especially advantageous that the closure according to the invention can be employed for all conventional fuels up to and including the closure of electrical connections. In addition, the closure requires no additional external flap but rather can be disposed so as to be freely accessible on the body of automobiles. The principle according to the invention enables simple operation with or without electrical drive. If an electric drive is provided, the closure is also suitable for use with robots. Owing to the additional reduction ratio created between the operating lever and closure part by the second guide slot, high sealing forces and a high degree of tightness of the closure can be ensured even with relatively small spring forces. If an electric drive is employed, the drive capacity required therefor may be kept low owing to the progressive reduction ratio resulting from the two guide slots. In addition, the complete closure may be configured such that it can be fitted and removed from outside in an especially simple manner.
According to one advantageous embodiment, the spring mechanism consists of at least one spring, which is fastened to the neck at one end and to the operating lever at the other and, during the closing movement of the closure part, exerts a pretensioning force on the operating lever in the closing direction at least from a specific pivot position of the closure part. Owing to the fact that the spring acts on the operating lever, the levering action of the operating lever can be employed in an especially effective manner. Alternatively or additionally to a spring of this kind, however, a spring that engages with the neck at one end and directly with the closure part at the other is also conceivable.
According to one advantageous embodiment, the spring is movable, during the closing and opening movement of the closure part, beyond a dead-centre position, between a first region beyond dead-centre and a second region beyond dead-centre, the spring exerting, in the first region beyond dead-centre, a pretensioning force on the closure part in the closing direction whereas, in the second region beyond dead-centre, it exerts a pretensioning force on the closure part in the opening direction. This means that the closure part is pretensioned not only, on the one hand, in the direction of its closed position, but also, on the other, in the direction of its open position. Thus, depending on the side of dead centre on which the spring is located, the spring pretensioning force operates either in the closing direction or in the opening direction of the closure part.
An especially simple, space-saving embodiment may be realised in that the spring consists of a leg spring.
According to one advantageous embodiment, the operating lever is mounted on the neck by means of a fixed pivot bearing. Because the operating lever is mounted on the neck itself and not on a bearing component located outside the neck, a module is created that can be fitted and removed in an especially simple manner.
According to one advantageous embodiment, the first and second guide slots are configured for the closure part and the coupling between the closure part and the operating lever such that, on introduction of force via the operating lever, the closure part is movable both in the opening and in the closing direction. As a result, the closure can be both opened and closed in a fully-automatic manner.
According to one advantageous embodiment, on introduction of a closing force via the closure part, the movement of the closure part in the closing direction from its open position is sanctioned so that the closure part can be guided back into its closed position through direct manual operation. In this way, the closing of the closure is possible in an especially simple manner, manually and without operating any electric motors or other closure mechanism, in that the closure part is briefly pivoted in the closing direction from outside, whereupon the spring mechanism then guides the closure part fully into its final, tightly-sealed closed position.
According to one advantageous embodiment, the first guide slot comprises two guiding slots provided in a lateral wall of the neck and guiding pins provided on the closure part and engaging in the guiding slots, the guiding slots running such that the closure part is initially raised from the closed position in a perpendicular direction relative to the plane of the orifice and is subsequently tilted away laterally relative to the external wall of the neck. This creates a two-stage movement sequence, which enables the closure part to be raised from the orifice of the neck and placed on this orifice, in an especially low-friction and precise manner which conserves material.
If an electric motor is employed to open and close the closure, it is advantageous if the electric motor is connected to the operating lever via a gearbox without self-locking. This has the advantage that, in the event of a non-active or failed electric motor, the closure can be operated manually by an emergency operation without it being necessary to decouple the electric motor or gearbox.
According to one advantageous embodiment, the operating lever may be operated by means of a cable mechanism and/or a lever mechanism. This has the advantage that the closure part can be opened from the vehicle interior via the cable mechanism or lever mechanism, which is routed into the vehicle interior. An embodiment of this kind thus represents an especially useful safety device in the event of failure of the electric motor.
If no electric drive is to be employed, it is also perfectly possible to slow the movement sequences of the closure part by means of a braking element, which acts either on the operating lever or on the closure part.